(a) The function of the cornea is to allow the light to enter the eye. It is the front part of the eye.

(b) The function of the iris is to control the amount of light entering the eye.

(c) The function of the pupil is to control the illumination in the eye.

(d) The function of the ciliary muscles is to change the focal length of the eye-lens by changing its shape.

(e) The function of the eye-lens is to focuses light on to the retina.

(f) The function of the retina is respond to the intensity of light and colour of objects respectively with the help of rods and cones present in it.

(g) The function of the optic nerve is to convey the image formed on the retina to the brain.